Biochar derived from plant waste improves seedling growth by influencing the physical structure and nutrient content of simulated lunar soil

The utilization of native lunar soil and recycled organic waste as primary resources can effectively reduce reliance on terrestrial inputs and improve the self-sufficiency of bioregenerative life support system for future lunar bases. However, lunar soil differs considerably from Earth's soil as it lacks organic carbon and the associated nutrients necessary for plant growth. To address these challenges, biochar can be produced by recycling the organic waste generated in a BLSS. As an environmentally friendly amendment, biochar can enhance the structure and nutrient content of soil and promote plant growth. Therefore, the purpose of this study is to investigate the suitability of native lunar soil for plant growth and assess how its agronomic performance is affected by the addition of biochar derived from plant waste. Compared with the control treatment, rice straw biochar treatment significantly improved the physical and chemical properties of the lunar soil simulant (p < 0.05), increasing the organic matter content by 91.02 % and enhancing N availability by 69.68 %, P availability by 82.83 %, and K availability by 21.60 %. Redundancy analysis suggested that soil air porosity, total P, and available K, were critical factors influencing lettuce growth. The optimal amount of biochar to amend simulated lunar soil should be set at 3 %. The experimental findings demonstrated that the addition of biochar to the simulated lunar soil had positive effects on its chemical and physical properties, as well as its potential for supporting plant growth.